This week’s Sunday Times has an article about Bill Dunster, rightly described as one of Britain’s foremost green architects and pictured here at his home with wife Sue. He’s still best known as the designer of
BedZed, the south London housing scheme that sits at the top of every magazine and newspaper’s stock photo library and gets aired every time they want to illustrate a feature on low energy housing. His more recent work expands upon the reputation he established there and he’s sort of trademarked the Zed-bit so that anything with a Zed in it, like ZEDHomes or ZEDFactory, is likely to have Dunster’s imprint on it. It’s easy to overlook the fact that ZED, in this instance, stands for Zero Energy Development, a critical feature of all his designs.
But Dunster’s not without his foibles. One of the things he’s really into is thermal mass, which requires the use of tonnes and tonnes of concrete to act as a heat store for his houses. This is done to facilitate passive solar design, already discussed on the blog (see Feb 21st 2007 entry). But using masses of readymix concrete upsets a lot of greens because, well, it’s concrete. And it also upsets the MMC set, because you can’t sensibly prefabricate it in a factory.
He also manages to upset the PassivHaus crowd by rejecting mechanical ventilation with heat recovery and instead espousing wind-assisted passive stack ventilation. This is indeed the raison d’etre behind the massive multi-coloured cowls that sit on top of BedZed, which make the place both other-worldly and photogenic. As you can see, Bill Dunster is not everyone’s cup of green tea.
Personally, I don’t have a problem with using lots of concrete or not using any fans. He puts forward credible arguments for both viewpoints and is all for recapturing the carbon used to make the concrete over the lifetime of the buildings.
But there is one aspect of Dunster’s vision that does trouble me. That is his predilection for site-generated renewable power. In the quest to create zero carbon developments, Dunster seems to have gone overboard on installing renewable technologies, and wind turbines in particular, that really don’t make much sense. And the Sunday Times feature has an interesting clue as to why that might be. In discussing Bill and Sue Dunster’s own house in East Molesey, Surrey, it states “Last year, the Dunsters took great pleasure in disconnecting from mains gas.”
Just why should this fact be a cause for celebration chez Dunster? I am going out on a limb here and speculating that it all stems from a peculiarly British strand of green building, which seeks autonomous or self-sufficient development as an end in itself. There were the John Seymour books published in the 1970s which put forward self sufficiency as a desirable goal, and there were also Brenda & Robert Vales’s books, the Self Sufficient House and the Autonomous House. These plotted a vision where each house was a little island which produced its own food, generated its own energy and disposed of its own waste. These self-sufficient stirrings were being mirrored on the TV at the same time by the antics of Tom and Barbara in The Good Life, a sitcom set in Surbiton — very close as it would happen to East Molesey, home of Bill and Sue.
But I didn’t get self-sufficiency back in the 1970s and I still don’t get it. What is the point? We are social creatures, born to trade and barter, and we get ahead by specialising, by getting a skill set that others don’t have and by making ourselves useful to a wide number of people. Aiming to be self-sufficient seems to be running counter to all this: you need to be part gardener, part engineer, part builder and part composter. In fact, you need to be full time peasant. It may well suit some people but methinks not that many. Most people would prefer to live by their wits and get specialists to look after these aspects of their lives, which is why supermarkets, builders and utility companies always do good business, whatever the economic outlook.
Following on from this, the trends towards decentralised power and, in particular, on-site renewables seems to be driven in good part by a Tom & Barbara agenda. We have a country criss-crossed with energy supply lines, and we have professional power supply companies queuing up to deliver renewably generated electricity into the grid, planning problems not withstanding. Yet at the same time we are being encouraged to bake our own electricity on site, as if this in itself was a worthy goal, and despite the fact that common sense says it would be much more efficiently generated off site. There is now a healthy ongoing debate about just what exactly the definition of on site should be, at least from a power generation standpoint. Could it include a neighbourhood wind turbine? Or a combined heat and power plant for an estate? Or, heaven forbid, just buying green electricity from the grid. You might think it’s all a bit academic, but it’s a point that has become central to the definition of what a zero-carbon home may or may not be. And it’s become central to the work of Bill Dunster, because without on site renewables he can’t build a ZEDHome.
But does it really make sense as a model by which to power the carbon-lite economy? Or are on-site renewables just a throwback to 1970s woolly thinking?
Labels: Low Energy Homes